JPH0339434A - Production and product of fatigue crack- resisting nickel-base superalloy - Google Patents

Abstract

PURPOSE: To produce a Ni base superalloy excellent in fatigue crack resistance by preparing a Ni base superalloy contg. specified ratios of Co, Cr, Mo, Al, Ti, Ta, Nb, Zr, C, B and W at a specified cooling rate.

CONSTITUTION: An Ni base superalloy contg., by weight, 3 to 13% Co, 10 to 16% Cr, 2.5 to 5.5% Mo, 2.5 to 4.5% Al, 1.5 to 3.5% Ti, 2.0 to 5.0% Ta, 2.0 to 5.0% Nb, 0.00 to 0.10% Zr, 0.0 to 0.10% C, 0.01 to 0.05% B, 0.0 to 1.0% W, and the balance Ni is produced at a cooling rate of about ≤600°F/min. In this way, the Ni base superalloy improved in resistance to the generation of cracks can be obtd.

COPYRIGHT: (C)1991,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention It is well known that nickel-based superalloys are widely used in environments requiring high performance. Such an alloy is
Jet engines, land gas turbines and 1000°
It has been widely used in other engines where high strength and other desirable physical properties must be maintained at temperatures above F.F.

Many of these alloys have various volume fractions of γ′
Contains precipitates. This γ' precipitate is responsible for the high performance properties of such alloys at high service temperatures.

The characteristics of the phase chemistry of γ′ are Hall (E, L, Hall)
, Kouh (Y.M.) and Zhang (K.M.
Chang), ``Phase Chemistry in Precipitation Strengthening of Superalloys''.
prectpttatton-strengthen+
ng 5uperalloy) J [August 1983
Monthly American Society of Electron Microscopy Section 41st Pension Newsletter (P
roceedingS or 41st Annual
Meeting of Electron Mlcr
oscopy 5oc1ety or America
), page 248].

U.S. Patent Nos. 2.570,193 and 2,621.12
No. 2, No. 3,046,108, No. 3゜061.426
No. 3,151,981, No. 3.166.412, No. 3,322.534, No. 3.343,950,
No. 3.575,734, No. 3,576.861, No. 4. 207. No. 098 and No. 4,336.312
No. 1 discloses various nickel-based alloy compositions. These patents are representative of the many developments in alloying that have been reported to date, with various physical and mechanical properties aimed at capturing different functional relationships between elements. Many of the same elements are combined so that phases are formed that result in an alloy system. But from Mu,
Despite the wealth of data available regarding nickel-based alloys, it is difficult for those skilled in the art to predict the physical and mechanical properties that such alloys formed using known combinations of elements at certain concentrations may exhibit. , especially when such combinations fall within the broad teachings prevailing in the industry, and when the alloy is processed using a heat treatment different from that traditionally used, some degree of precision may not be possible. It is still impossible to predict the difference.

An increasingly important and recognized problem with many such nickel-base superalloys is their susceptibility to crack formation or the appearance of cracks, either during manufacture or during use. Moreover, during use of the alloy in structures such as gas turbines, jet engines, etc., the cracks can actually propagate or grow larger under stress. Propagation and expansion of cracks can result in component destruction or other failure.

The consequences of failure of moving mechanical parts due to crack initiation and propagation are well understood. Jet engines can be especially dangerous.

However, what was not very well understood until recent research was that the initiation and propagation of cracks in structures made of superalloys was caused by the same mechanism,
This means that they are not simple phenomena that occur and propagate at the same speed and according to the same criteria. In contrast, crack initiation and propagation and crack phenomena in general are complex, and important new information has been gathered in recent years on the interrelationship between such propagation and stress application.

The length of time a member is stressed before a crack initiates or propagates, the intensity of the stress, the rate at which the member is stressed or removed, and the planned schedule for applying this stress.
The fact that the impact of a program varies depending on the alloy is shown in the (U.S.) National Aerospace Box.
Aoronautlcs and 5pace Adm
It was not well understood until a study was conducted under contract with Nistratlon. This research is reported in NASA CR-165123, which was published in August 1980 by the US National Aerospace Box.
tlcs and 5pace Adslnistra
Cowles (B, A, Cov) published by tlon)
Eval uat t
Honor the Cyclic Behavior
or＾Ircraft Turbine Dlsk A
11oys) Part II of J is considered to be the final report. This report is based on the (United States) National Aerospace Box (Na
tional Aeronautics and 5p
ace Adslnlstration), NA
S.A. Lewis Research Center
e5earch Center), contract NAS3-21
This was done for 379.

A key finding of this NASA-sponsored study was the fatigue phenomenon-based propagation velocity, or fatigue crack propagation (F CP
) is not uniform for all applied stresses, and is also not uniform for all ways of applying stress. Even more important is the discovery that fatigue crack propagation does indeed vary with the frequency with which stress is applied to the member to propagate the crack. Even more surprising, a significant finding of the NASA-sponsored study is that applying stress at a lower frequency than the high frequencies used in past studies actually increases the rate of crack propagation. In other words,
This NASA study confirmed that fatigue crack propagation is time dependent. Furthermore, it has been found that the time dependence of this fatigue crack propagation does not depend only on the frequency, but also on the length of time that the component is held under stress, ie the so-called holding time.

After demonstrating that the extent of increased fatigue crack propagation at lower stress frequencies was unusual, industry was encouraged by this newly discovered phenomenon to use nickel-based superalloys in stressed components of turbines and aircraft engines. It was believed that the possibilities for use were ultimately limited and that every design effort must be made to design around this problem. However, it has been discovered that parts of nickel-based superalloys can be constructed with significantly reduced crack propagation rates and good high temperature strength for use at high stresses in turbines and aircraft engines.

It is known that the most desired set of properties for superalloys are those needed for jet engine construction. Although the set of required properties will vary depending on the different elements of the engine, typically those required for the moving parts of the engine will be the same as those required for the fixed parts. more important and numerous than what is said to be.

Because a certain set of properties is not available with cast alloy materials, powder metallurgy techniques may have to be used to manufacture the parts. However, one of the limitations associated with using powder metallurgy techniques in the manufacture of moving parts for jet engines is the issue of powder purity. If the powder contains impurities such as small particles of ceramic or oxides, the point in the moving part where the particles are located becomes a potentially weak point where cracks can begin. Such weak points are essentially potential cracks. The possibility of the existence of such latent cracks makes the problem of reducing and inhibiting the rate of crack propagation all the more important.

The inventor has discovered that it is possible to suppress crack propagation by applying both the :A adjustment of the alloy composition and the manufacturing method of such a metal alloy.

The present invention provides a superalloy that can be produced using powder metallurgy techniques. Also provided is a method of processing this superalloy to produce a material with an excellent set or combination of properties for use in state-of-the-art engine disk applications. Properties traditionally required for materials used in disk applications include high tensile strength and high stress fracture strength. Additionally, the alloys of the present invention exhibit the desirable property of resisting time-dependent crack growth propagation. Resistance to such crack growth is essential to the low cycle fatigue (LCF) life of the component.

As alloy products for use in turbines and jet engines have been developed, it has become apparent that different sets of properties are required for the components used in various parts of the engine or turbine. In the case of jet engines, the requirements for more advanced aircraft engine materials continue to become more stringent as aircraft engine performance requirements increase. This requirement is substantiated, for example, by the fact that many blade alloys exhibit very good high temperature properties in the cast state. but,
Since blade alloys exhibit insufficient strength at intermediate temperatures,
Direct conversion of cast blade alloys to disk alloys is highly unlikely. Additionally, blade alloys have proven to be extremely difficult to forge, and forging has proven desirable for producing disks from disk alloys. Furthermore, the crack growth resistance of the disk alloy has not been evaluated. Therefore, it is always desirable to improve the strength and temperature performance of disk alloys as part of special alloys used in aircraft engines in order to derive increased engine efficiency and greater performance.

Therefore, what was desired in carrying out the research that led to the present invention was the development of a disk alloy with low or moderate time dependence of fatigue crack propagation and high fatigue crack resistance. Ta. Also desired was a balance of properties, particularly tensile properties, creep properties and fatigue properties.

What was further desired was the strengthening of established alloy systems with respect to inhibiting crack growth phenomena.

The development of the superalloy composition and processing method thereof of the present invention focuses on fatigue properties, particularly addressing the time dependence of crack growth.

It is known that crack growth, or crack propagation rate, in high strength alloy objects depends on the applied stress (σ) and the crack length (a). When these two factors are combined by fracture mechanics, they form a single crack growth driving force, the stress intensity factor.
city factor) becomes K.

This factor is proportional to σ, /T. Under fatigue conditions, this stress intensity during a fatigue cycle can consist of two components: a repetitive component and a static component.

The former is the maximum change in repeated stress degree (ΔK), that is, K
Illax and. represents the difference between At moderate temperatures, crack growth primarily affects the static fracture toughness KI.

It is determined by the degree of repeated stress (ΔK) until .

The crack growth rate is expressed mathematically as da/dNoc(ΔK)n. N indicates the number of cycles, n depends on the material. Repetition frequency and waveform shape are important parameters determining the crack growth rate. For a given cyclic stress level, a smaller cyclic frequency can result in a faster crack growth rate. This undesirable time-dependent behavior of fatigue crack propagation can be seen in most high strength superalloys. Adding to the complexity of this time-dependent phenomenon, raising the temperature above a certain point;
A crack can grow under static stress of some intensity without any cyclic component (i.e. -0 on Δ). The design goal is to find a value of da/dN that is as small as possible and as time-independent as possible. The stress intensity components can interact with each other over a certain temperature range such that crack growth is a function of both cyclic and static stress intensity, ie, Δ and K.

DETAILED DESCRIPTION OF THE INVENTION Accordingly, one object of the present invention is to provide a nickel-based superalloy with increased resistance to cracking.

Another object is to provide a method for reducing the tendency of established known nickel-based superalloys to crack.

Another object is to provide an article with increased resistance to fatigue crack propagation when used under repeated high stresses.

Furthermore, another object is to provide compositions and methods that allow nickel-based superalloys to be rendered resistant to cracking under repeated applied stresses over a range of frequency numbers. .

Some of the other objectives will be apparent from the description below, and some will be pointed out below.

In one of its practical aspects, the object of the invention can be achieved by providing a composition having the following general composition.

Component Concentration in composition (wt%) (lower limit amount)
(Upper limit ff1) Ni Remainder Co 3-13 Cr10-16 Mo 2. 5-5.5A1
2.5~4.5Ti
1.5-3.5Ta 2. 0-5
．． ONb 2. 0~5.0Z
rOl 0~0.10COl 0
~0.10B O,01~0.05W
Ol 0-1. The object of the present invention can also be achieved in one of its other aspects by providing a composition having the following general composition.

Component Concentration in composition (wt%) Ni C.

r O 1 (Lower limit amount) - (Upper limit amount) Remaining 3-13 10-16 2.5-5.5 2.5-4.5 Til, 5-3.5Ta2
．． 0-5. O Nb 2. 0-5.0 Reo, 0
~3.0HfO,0~0.6Zr
o, 0-0. 10C060~0.1
0 B O, 01~0.05W
0.0~1.0y
o,o~0,2 The following detailed description will be better understood with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION By studying currently commercially available alloys used in structures requiring high strength at high temperatures, the inventors have discovered that conventional alloys have a pattern. This pattern is based on the final revision of NASA No. CR-1651.
This is based on plotting the data in No. 23 using a method devised by the present inventor. The inventor was born in 1980.
Data from this NASA report for the year was plotted using the parameters shown in Figure 1. As is clear from Figure 1, the data are arranged almost diagonally.

In FIG. 1, crack growth rate (C inches/cycle) is plotted against ultimate tensile strength (ksi). Individual alloys are indicated on this graph by a plus (+) symbol, which is the corresponding property of that alloy at its characteristic ultimate tensile strength (ksi) value. The crack growth rate (in/cycle) is shown. As can be seen, the straight line labeled 900 seconds residence time shows the characteristic relationship between crack growth rate and ultimate tensile strength for these previously known alloys.

At the bottom of this graph, a similar point corresponding to the + symbol point shown is shown for a crack propagation rate test conducted at 0.33 hertz (Hz) or, in other words, at a higher frequency. The data shown as diamonds lies in the region along the line labeled 0.33 Hz for each alloy shown at the top of this graph.

It is clear from Figure 1 that for long residence times there is no alloy composition with the coordinates in the lower right corner of this graph. In fact, all the data points for the longer dwell time crack growth tests are along the diagonal of this graph, so any alloy composition that forms will be located somewhere along the diagonal of this graph. It seemed like it would be.

In other words, it appeared that the parameters plotted in FIG. 1 did not allow one to find an alloy composition that had both high ultimate tensile strength and low crack growth rates at long residence times.

However, the inventors have discovered that it is possible to produce alloys with compositions that are capable of achieving a unique combination of high ultimate strength and low crack growth rates.

One of the conclusions reached hypothetically by the inventors was that chromium concentration could have an effect on the crack growth rate of various alloys. For this reason, we plotted chromium content (fffffi%) against crack growth rate. The results of this plot are shown in FIG. In this figure, it can be seen that the chromium content varies from about 9% to about 19%, and the corresponding crack growth rate measurements show that the crack growth rate decreases with progressively increasing chromium content. There is. Based on this graph, it appeared that it might be extremely difficult or impossible to devise an alloy composition with low chromium content and at the same time low crack growth rate at long residence times.

However, the inventor has discovered that when the components of certain superalloy compositions are combined and properly alloyed, it is possible to form compositions with low chromium content and low crack growth rates at long residence times. I found out.

FIG. 3 shows an example of the relationship between the holding time when stress is applied to a test piece and the rate at which crack growth changes.

In this figure, the logarithm of the crack growth rate is plotted on the vertical axis and the residence time or holding time (seconds) is plotted on the horizontal axis. 5X1
A crack growth rate of 0' means that the cyclic stress factor is 25 k
The case of s i / i n may be seen as the ideal speed. If an ideal alloy is formed,
The alloy will exhibit this rate throughout the crack or hold time stressing the specimen. Such a phenomenon is represented by straight line (a) in FIG. This straight line indicates that the crack growth rate is essentially independent of the holding or residence time while stressing the specimen.

In contrast, the curve (b
). It can be seen that for very short holding times, up to a few seconds, the ideal line (a) and the practical curve (b) do not deviate too much. When stressing the sample at such high frequencies or low holding times, the crack growth rate is relatively low.

However, as the holding time to stress the sample increases, the experimental results for conventional alloys follow curve (b). Therefore, it can be seen that as the frequency of stress loading becomes lower and the holding time required for stress loading becomes longer, the deviation from the linear velocity increases. It is clear from the 'ff13 diagram that by arbitrarily choosing a holding time of about 500 seconds, the crack growth rate can be increased by a factor of 100 from the standard rate of 5x10-5 to 5x10'.

Again, it would be desirable if the crack growth rate were independent of time, and this is ideally represented by following curve (a) as the holding time increases and the stress is applied less frequently. Probably.

Surprisingly, the inventors have discovered that by making small changes in the composition of the superalloy, it is possible to greatly improve the alloy's resistance to long residence time crack growth propagation. In other words, it has been found that it is possible to reduce the rate of crack growth by modifying the alloying.

Furthermore, it is also possible to increase the strength by processing the alloy.

An alloy designated as tip example HK81 was produced. The composition of this alloy is essentially as follows.

Minutes Concentration (wt%) Ni Remainder Co 8 C “13 Mo 3.5 Al 3.5 Ti 2.5 Ta 3.5 Nb 3.5 Re　　　　　O,O Hf　　　　　　　　　　　O,O Zr　　　　　　　　　0,06 CO,05 B O, 03 y　　　　o,.

This alloy was subjected to various tests, and the test results were
Plotted in Figure 0. Here, the alloy for which data was collected for the material treated with "Super Solvus" is r-SSJ.
It is expressed by adding the letters . That is, the high temperature solid state heat treatment performed on this material was above the temperature at which the reinforcing γ' precipitates dissolve, but below the initial melting point. This usually results in a coarser grain size in the material. The reinforcing γ' phase precipitates again during subsequent cooling and special treatment.

Referring now to FIG. 4, this graph shows H
For K81-SS and Rene' 95-8S samples, fracture life (hours) and cooling rate (F7 minutes)
It is plotted against. As is clear from this graph, for the HK81-8S sample, the fracture life is over 175 hours when the sample is cooled at approximately 75°F/min, which increases to approximately 350 hours when the sample is cooled at over 1000°C/min. Extended. The fracture life of HK81-8S was Rone's at all cooling rates tested.
It is shown that it is superior to 95-8S.

A similar but not identical graph is shown in FIG. In FIG. 5, the equivalent temperature is plotted on the vertical axis for a sample having a stress rupture life of 100 hours. In other words, the plot in Figure 5 is 80 ksi in argon.

It shows the temperature at which the sample tested at 1400″F withstood for 100 hours. Again, the difference in temperature at which stress failure lasted for 100 hours versus cooling rate is evident from the graph.

FIG. 6 is a plot of crack propagation rate (in/cycle) versus cooling rate ('F/min). Reneo 95-SS and HK81-3S samples were tested in air at 1200°C with a hold time of 500 seconds at maximum stress factor. Clearly, HK81-3S has a much lower crack growth rate than RAENE' 95-SS for samples cooled at 75'F and 350'F. The da/dN of the sample cooled at a rate of 1000° C. or higher is somewhat lower than that of the Rene' 95-SS sample cooled at the same rate. One range of cooling rates suitable for producing components from such superalloys is from 100'F/min to 600'F/min.
It should be noted that it is expected to be in the range of minutes.

As can be seen from the foregoing, the present invention provides an alloy with a unique combination of both the types of components and their relative concentrations. It is also clear that the alloy proposed by the present invention has novel and unique capabilities in terms of crack propagation inhibition. It is clear from Figure 6 that HK81-
The low crack propagation velocity da/dN of the 3S alloy is a novel and impressive result unique to the present invention. A d of about 4.5X10' found in a sample cooled at about 400"F/min.
When a/d N is plotted in FIG. 1, it is located in the lower right corner of the plot in FIG. 1 and below the 0,33 Hz line shown in the plot.

Similarly, with respect to Figure 2, the data points for the above HK81-6S alloy with 13% chromium and 4.5X10-5 da/dN are well below the long residence time line;
It is very close to, but below, the fatigue growth rate line for the 0.33 Hz test.

The test data shown in Figure 6 is for a retention time of 500 seconds, and the plot in Figure 2 is for a retention time of 900 seconds. Based on this, the data points for the above alloys should be much closer to the 900 seconds line than they are closer to the 0.33Hz line.

However, what appears to be exactly the opposite.

This is despite the fact that small differences can make a dramatic difference and are very critical in reducing crack propagation rates, especially in long cycle fatigue tests.
This is quite surprising since the composition differs only slightly from that found in the Rene') 95 alloy. This small difference in components and their proportions results in an unexpectedly significant low fatigue propagation velocity along with a highly desirable set of strength and other properties, as is evident from the graphs in the drawings accompanying this application.

Other properties of the alloy of the present invention will be explained below with reference to FIGS. 7-10.

The alloys of the present invention are Rene' 9 in several respects.
5 and to provide a basis for comparing the respective alloys with the alloy of the present invention and Rono' 95-8.
Comparative tests were conducted on samples of S. Of these test results, those obtained at 750''F are plotted in Figures 7-8, and those obtained at 1400''F are plotted in Figures 9-10.

First, reference is made to the test data plotted in FIG. Figure 7 shows two alloy samples HK81-8S and Rene' 95-8 tested at 750''F.
For S, yield stress (kst) and cooling rate (F7 min)
The relationship between is plotted.

In this port, Rene' 95-S
The superiority of the HK81-SS alloy sample compared to the S sample is obvious. HK81-SS and Rene
' ) 95-SS samples were all produced by powder metallurgy techniques and are therefore very similar to each other in terms of strength and other properties.

FIG. 8 shows Alloy 1 (KH
2-3S sample and Rcneo for comparison.
)95-3S sample, the ultimate tensile strength (ks
is plotted against the cooling rate (77 minutes). The sample tested was measured at 7501:. Rene (
It is well known that Rene') 95 is one of the strongest known commercially available superalloys. As is clear from Fig. 8, the results of ultimate tensile strength measurements conducted on samples of HKIII-5S alloy and Rene' 95-SS alloy are as follows:
HK81-8S alloy is a reality Rene' 95
- It has been demonstrated that it has a higher tensile strength than SS materials, especially its ultimate tensile strength.

As is clear from the plot in Figure 9, the alloy has 1
The yield strength at 400°C ranges from about 148 for alloy samples cooled at about 75″F/min to yield strengths of 170 or higher for samples cooled at 1000°F/min or more.

Therefore, referring to Fig. 10, both are 140″F
Two samples were tested, namely Rene'
) 95-SS and HK81-SS, 140
The relationship between ultimate tension at 0 and cooling rate (F7 min) is plotted.

The data presented in Figures 9-10 further demonstrate that the alloys of the present invention have a set of strength properties (1400"F) that are superior to those of Rene' 95 at 1400"F. It has also been proven that

Furthermore, with respect to inhibiting fatigue crack propagation, the alloys of the present invention are capable of achieving speeds ranging from 100"F/ to 600"F/
This is far superior to alloys produced at a cooling rate of minutes.

What is remarkable about the effects of the present invention is Rene'
With relatively small changes in the composition of the HK81 alloy compared to the composition of the 95 alloy, fatigue crack propagation resistance is significantly improved.

To illustrate small changes in alloy composition, Rene
') The ingredients of both 95 and HK81 are listed below.

Ni 62.36 62.36Co
8 r 3 Mo 3. 5 3. 5W
3.5 Al 3.5 3.5Ti
2,5 2.5Ta
3. 5Nb
3.5 3.5f Zr O,060,06 Re CO,050,05 B O,030,03 e As is clear from Table 1 above, the composition of alloy Rono'' 95 is lower than that of alloy HK81. The significant difference in composition is that Rcne' 95 contains 3.5% tungsten and no tantalum, whereas HK81 contains no tungsten but 3.5% by weight.
The only difference is that it contains tantalum.

In other words, the composition of Rene' 95 has been altered by omitting 3.5% by weight of tungsten and including 3.5% by weight of tantalum. It is rather surprising that such compositional changes can preserve or improve the basic strength properties of the Rene' 95 alloy while at the same time improving the alloy's fatigue crack suppression at long residence times. This seems to be the case. However, this is precisely the result of compositional changes, as evidenced by the data listed in the accompanying drawings and detailed above.

Changes in tungsten and tantalum additives are responsible for significant changes in fatigue crack propagation inhibition.

Other changes in the components that are not related to the above-mentioned significant changes in properties, particularly changes in the amount of added components, may be made. For example, small amounts of rhenium may be added without altering the unique combination of properties found in the HK-811 alloy, particularly without detracting from such properties.

Although the alloys of the present invention have been described in terms of components and percentages of components that provide uniquely advantageous proportions with respect to crack propagation inhibition, other components, such as yttrium,
It will be appreciated that vanadium and the like can be included in the composition in percentages that do not interfere with the novel crack propagation inhibition. Small amounts of yttrium, for example on the order of 0-0.62%, can be included in the alloys of the present invention without detracting from the unique and valuable combination of properties of the alloys.

[Brief explanation of drawings]

FIG. 1 is a graph plotting fatigue crack growth (inches/cycle) against ultimate tensile strength (ksi) on a logarithmic scale for fatigue crack propagation at 650° C. (ΔK at 30 ksl). FIG. 2 is a graph plotting the same test results as in FIG. 1, but the horizontal axis represents the chromium content (% by weight). FIG. 3 is a graph plotting the logarithm of the crack growth rate against the holding time (seconds) when stress is repeatedly applied to the test piece. Figure 4 shows the fracture life (hours) when a stress of 80 ksl is applied at 1400'F in argon and the cooling rate (F7
This is a graph plotted against (minutes). FIG. 5 is a graph in which the temperature (F) at which a life of 100 hours can be expected at 80 ks i is plotted against the cooling rate (77 minutes). Figure 6 shows the crack propagation rate d in inches/cycle.
Figure 2 is a graph plotting a/dN against cooling rate (F7 min). Test conditions: under 1200, in air,
R-0,05,500 seconds retention time, 25kslv/T
? Figure 7 is a graph of yield stress (ksi) at 750''F plotted against cooling rate (bottom 7 minutes) on a logarithmic scale. Figure 2 is a graph of ultimate tensile strength (ksi) at 750''F plotted against speed (F7 min). Figure 9 shows 1 plotted against the cooling rate (F7 min).
2 is a graph of yield stress (ksi) at 400°F. FIG. 10 is a graph of ultimate tensile strength (ksi) at 1400° F. plotted against cooling rate (F7 min).

Claims (9)

[Claims] (1) Alloy composition containing the following components in the following proportions: Ingredients Concentration in composition (wt%) Ni remainder Co3~13 Cr10-16 Mo2.5~5.5 Al2.5~4.5 Ti1.5~3.5 Ta2.0~5.0 Nb2.0~5.0 Zr0.00~0.10 C0.0~0.10 B0.01~0.05 W0.0-1.0. 2. The composition of claim 1, wherein the composition is cooled at a rate of no more than about 600°F/min. 3. The composition of claim 1, wherein the composition is cooled at a rate of 50 to 600 F/min. (4) Alloy composition containing the following components in the following proportions: Ingredients Concentration in composition (wt%) Ni remainder Co3~13 Cr10-16 Mo2.5~5.5 Al2.5~4.5 Ti1.5~3.5 Ta2.0~5.0 Nb2.0~5.0 Re0.0~3.0 Hf0.0~0.5 Zr0.00~0.10 C0.0~0.10 B0.01~0.05 W0.0~1.0 Y0.0-0.2. 5. The composition of claim 4, wherein the composition is cooled at a rate of no more than about 600°F/min. 6. The composition of claim 4, wherein the composition is cooled at a rate of 50 to 600 degrees F per minute. (7) Alloy composition containing the following components in the following proportions: Ingredients: Concentration of composition width (wt%) Ni remainder Co8 Cr13 Mo3.5 Al3.5 Ti2.5 Ta3.5 Nb3.5 Zr0.06 C0.05 B0.03. 8. The composition of claim 7, wherein the composition is cooled at a rate of no more than about 600°F/min. 9. The composition of claim 7, wherein the composition is cooled at a rate of 50 to 600 degrees F per minute.